Uniflow two-stroke cycle internal combustion engine



Sept. 6, 1932. s. MJUDALE ET AL 1,875,523

UNIFLOW TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Original Filed Aug. 14, 1929 5 Sheets-Sheet 1 VENTOR CL racm TEUXEJLL .Ae.

STfl/VLEY M 0044.5 BY E ATTORNEY Sept. 6, 1932. v s. M. UDALE ET AL 1,875,523

UNIFLOW TWQ-STROKE dYCLE INTERNAL COMBUSTIQN ENGINE Original Filed Aug. 14, 1929 5 Sheets-Sheet 2 INVENTOR (z YOE w THU/(ELL Jlev STfl/VLEY n. UOHLE BY ATTORNEY Sept. 6, 1932. s. M. UDALE ET AL I UNIFLOW TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Original Filed Aug. 14. 1929 5 Sheets-Sheet 5 ATTORN EY N Q Q lllnll in u i I INVENTOR CLVDE w "reuxsu. vie. arm/v45) M. UOHLE,

Patented Sept. 6, 1932 UNITED STATES PATENT OFFICE STANLEY M. UDALE AND CLYDE W. TRUXELL, JR, F DETROIT, MICHIGAN, ASSIGNORS,

IBY MESNE ASSIGNMENTS, TO GENERAL MOTORS CORPORATION, OF DETROIT, MICH- IGAN, A CORPORATION OF DELAWARE UNIFLOW TWO-STROKE CYCLE INTERNAL COMBUSTION ENGINE Application filed August 14, 1929, Serial No. 385,899. Renewed December 4,1931.

The object of this invention is to arrange the air entrance through ports in the cylinder wall uncovered by the piston when at the bottom of its stroke so as to keep the head of the piston cool; to arrange the exhaust valve in the head of the combustion chamber so that the combustion chamber is always maintained at a relatively high temperature and the cylinder wall and piston at a relatively low temperature at all times.

. The specific object of this invention is to improve the operation of the two-stroke cycle oil injection engine.

Figure 1 shows the engine in cross sectional elevation on the plane 11 of Figure 3,

Figure 2 shows the invention in cross sectional elevation on the plane 2- 2 of Figure 3, and

Figure 3 shows the plane 33 of Figure 1.

In the drawings, Figure 1, A is the fuel nozzle located centrally within and discharging radially across the combustion chamber B. CO are the two exhaust valves arranged symmetrically with reference to the nozzle A. D is the cylinder liner preferably made of perlitic iron 2.5 C. 2.5 silicon. This liner is shrunk into the cylinder casting E which is water jacketed and provided with an outer wall F. Z is the two-stroke piston adapted to reciprocate in the liner D. The lower larger end of the piston Z reciprocates in the lower cylinder liner G which is shrunk into the lower part of the cylinder block E. F.

Piston Z is connected to the crank shaft J by the connecting rod K and a wrist pin L. It will be noted that the drawing shows a two-cylinder engine with a crank shaft J having two throws at 180 and that similar letters refer to similar parts as the two halves of the engine are identical.

- Air compressed in the lower cylinder G by the piston Z passes through the passage M into the adjacent cylinder, being admitted through the ports N, which ports are in line plan view taken on thewith similar ports in the casting E. These ports are so shaped as to give a rotary motion to the inlet N. Meanwhile air is admitted to the adjacent cylinder G through the inlet valve 0 which is of a well-known automatic type used in air compressors.

The sprocket P on the extreme left end of the crank shaft J engages with a chain indicated diagrammatically by a broken line Q, Figure 2. This chain Q engages with a sprocket R (also shown by broken line), which operates the fuel pump S which is also of a well-known type. Pipe T conveys the fuel to the nozzles A.

It will be noted that the cylinder head is 59 water jacketed through a jacket having a water outlet U. The water entrance is not shown but may be at any convenient place in the lower portion of the jacket F l The chain Q, also engages with a sprocket 5 W which operates a cam shaft W which in its turn operates push rods X which engage with rocker arms Y, which in their turn engage with the valves C in the well-known manner.

0pemtion.In the drawings, when the engine is operating with the crank J J in the position shown the right hand piston Z is ascending. Meanwhile air has been compressedin the left hand cylinder G and is conveyed through the pipe M, Figure 3, through the ports NN into the right hand cylinder D. At the same time fuel has beeninjected through A and is dischar ed horizontally across'the exhaust valves 0 above the head of the piston Z, in the left hand combustion chamber B. All of the surfaces of B are relatively hot compared with the water cooled surfaces of the cylinder and cylinder head so that combustion is facilitated even at low loads and speeds. Owing to the rotary motion which the air received when it entered the cylinder through theports N and the fact that there is no obstruction to prevent the rotation continuing and also because the time intervals are so short, the air in the combustion chamber B is rotating quite rapidly and hence the fuel particles issuing from A radially come into immediate contact with the'rotating fresh air in B and are therefore immediately and completely burned. The left hand piston Z then descends and the right hand piston Z ascends. Toward the end of the stroke the valves CC are opened by the cams W and at the same time the piston Z uncovers the ports NN so that air is driven into the cylinder D from one end and the exhaust is thus pushed out past the exhaust valves C at the other. The displacement of the compression cylinder B is such that at least 50% scavenging air is forced into the upper cylinder D. The reason for this is that not only is it desirable to get a complete scavenging of the burnt products of combustion but also it is desirable to blow a little cool air through the exhaust valves C, and finally, it is desirable to get a slight supercharging effect in the cylinder D.

What we claim is:

1. A uni-flow two-stroke cycle oil engine comprising a crank shaft, a cylinder, a piston therein connected to said crank shaft, airinlet ports located in the lower portion of said cylinder so as to be uncovered by said piston, said ports being so formed as to give to the entering air a rotary motion within said cylinder, a cylinder head, a plurality of exhaust valves in said head, a fuel nozzle in said head located in the center of said head and discharging radially outwards and across said exhaust valves, means for admitting compressed air to said air entrance and liquid fuel under pressure to said fuel nozzle.

2. A two-stroke oil engine comprising a crank shaft having throws at 180, a plurality of cylinders, pistons therein connected to said crank shaft, a two-diameter cylinder, a piston therein connected to said crank shaft, said pistons fitting both diameters of said cylinder forming an upper combustion chamber'and a lower, annular air pump, inlet ports located in the lower portions of said combustion chamber so as to be uncovered by said piston, said ports being so formed as to give to the entering air a rotary motion within said combustion cylinder, passages connecting the adjacent annular air pump cylinders with the combustion cylinders whereby air is forced by the air pump cylinders into and through the combustion cylinders, a cylinder head, a plurality of exhaust valves in said head, a fuel nozzle in said head located in the.

center of said head and discharging radially across said exhaust valves, means for admitting liquid fuel under pressure to said fuel nozzle.

3. In a two-stroke cycle engine a combustion chamber comprising a plurality of exhaust valves, a fuel nozzle located symmetrically with reference to and discharge ting rotating compressed air to said combus- 4 tion chamber means for admitting liquid fuel under pressure to said fuel nozzle.

5. In a two-stroke engine a flattened cylindrical combustion chamber, an exhaust valve therein, a fuel nozzle adapted to discharge fuel centrally of the combustion chamber radially outwards and across said exhaust valve, means for admitting rotating compressed air to said combustion chamber and means for admitting liquid fuel under pressure to said fuel nozzle.

6. In a two-stroke cycle engine a combustion chamber an exhaust valve opening therein, a fuel nozzle centrally located therein and adapted to discharge fuel radially outwards and across said exhaust valve, 3. cylinder communicating with said combustion chamber, a piston therein adapted to compress air into said air combustion chamber, ports in said cylinder adapted to give the entering air a rotary motion, and means for admitting fuel under pressure to said fuel nozzle.

7. The method of operating two stroke cycle internal combustion engines of the automatic ignition fuel injection type having a cylinder and a piston; said method consisting in admitting a charge of compressed air over the top of the piston when the piston is at the bottom of its stroke, further compressing the charge of air within the cylinder during the upward stroke of the piston and injecting fuel centrally of the cylinder and radially outwards so that the charge of fuel injected into the compressed air automatically ignites, expanding the burning charge durin ward stroke of the piston and riving the burnt charge out of the cylinder through an opening in the head of the cylinder by means of the charge of compressed air which is again admitted over the top of the piston into the 1 cylinder.

8. The method of operating two stroke cycle internal combustion engines of the automatic ignition fuel injection type having a cylinder and a piston; said method consisting 1 in so admitting a charge of compressed air over the top of the piston when the piston is at the bottom of its stroke that the charge of air rotates around the axis of the cylinder,

further compressing the charge of air within 1 the cylinder during the upward stroke of the piston and injecting fuel centrally of the cylinder and radially outwards so that the charge of fuel injected into the rotating compressed air automatically ignites, expanding the burnl the down- 1 ing charge during the downward stroke of the piston and driving the burnt charge out of the cylinder through an opening 1n the head of the cylinder by means of the rotating charge of compress air which is again admitted over the top of the piston into the oylinder.

In testimony whereof we aflix our signatures.

STANLEY M. UDALE. CLYDE W. TRUXELL, JR. 

